1. Technical Field
The present disclosure relates to a thin film transistor substrate and, more particularly, to a thin film transistor substrate having a reduced size obtained by constructing data signal supply lines, each of which supplies a pixel data voltage to a data line, with different metal lines, respectively, and a fabricating method thereof.
2. Discussion of Related Art
Generally, a liquid crystal display (“LCD”) device includes an LCD panel displaying an image, a driving circuit driving the LCD panel, and a light source unit supplying light to the LCD panel.
The light source unit includes a light source, such as a lamp or a light emitting diode, to emit light, a light guide plate guiding the light from the light source to the LCD panel, a reflective sheet reflecting and directing the light toward the light guide plate, and optical sheets provided between the light guide plate and the LCD panel to equalize the light luminance from the light guide plate.
The driving circuit includes a gate driving circuit driving a gate line of the LCD panel, a data driving circuit driving a data line, a power unit supplying power to the gate and data driving circuits, and a timing controller supplying control signals to the gate and data driving circuits.
The LCD panel includes a thin film transistor (“TFT”) substrate having a TFT array formed thereon, a color filter substrate having a color filter array formed thereon and facing the TFT substrate, and liquid crystals inserted between the TFT substrate and the color filter substrate.
The color filter substrate includes a black matrix on a transparent substrate to prevent light leakage, a color filter in pixel areas partitioned from one another by the black matrix, and a common electrode on the color filter to supply a common voltage.
The TFT substrate includes a pixel electrode on each pixel area and a TFT connected to the pixel electrode. In this case, the gate line supplies a scan signal from the gate driving circuit to a gate electrode of the TFT. The data line supplies a pixel data signal from the data driving circuit to the TFT each time the scan signal is supplied to the gate electrode. Accordingly, the pixel electrode is charged with the pixel data signal.
A separate signal line extending from the data line to be connected to the data driving circuit is additionally formed along a non-display area to supply the pixel data signal from the data driving circuit to the data line. In this case, because the signal line is formed of the same metal as the data line, it is unable to prevent signal interference or a short circuit between the signal lines unless a gap between the neighboring signal lines is maintained to exceed at least 4 μm.
When the gap between the neighboring signal lines is maintained to be about 4 μm, however, the size of the non-display area increases in proportion to the number of the data lines. Hence, the size of the TFT substrate increases.